Musical instrument



Aug. 29, 1939.

F. H. KISLINGBURY IUSICAL INSTRUMENT Filed July `26, 1937 4f, 2% @if 25 a? ,er

Patented Aug. 29,V 1939 UNITED STATES MUSICAL INSTRUMENT Fredray H. Kislingbury, Los Angeles, Calif., assignor vto Emil E. Dopyera, Los Angeles, Calif.

Application July 26, 1937, Serial No. 155,665

7 Claims.

This invention relates to musical instruments and relates more particularly to stringed musical instruments embodying electro-magnetic pick-up means. A general object of this invention is to provide a practical, yeffective stringed musical instrument embodying a novel electrical pick-up operable to convert the vibrations oi the strings into an electrical current having the characteristics of the vibrations of the strings.

l0 Another object of this invention is to provide a `stringed musical instrument of the violin vclass embodying an electro-magnetic pick-up unit that is operable to produce a varying or modulated electric current suitable for conversion into sound by an amplifying and loud speaker unit that permits the employment of vibratory strings of any character whereby the musician may provide the instrument with gut strings, metal strings, gut strings wound with silk or wire, or any other selected kinds of strings and may tension such strings as desired to obtain tones of the character, timbre and quality desired.

Where I herein employ the term instrument of the violin class" I mean instruments such as violins, cellos, violon-cellos, bass viols, guitars,

ukeleles, etc.

Another object of this invention is to provide an instrument of the character mentioned in which the electro-magnetic lpick-up creates a modulated 30' electric current that may be converted into sound having the-timbre, tonal qualities and other characteristics of the tones produced by the conventional instruments of the violin class. The instruments heretofore introduced having electrical pick-up devices have not been capable of faithfully or accurately reproducing violin tones. The instrument of the present invention, on the other hand, is operable to produce tones that are true violin typeinstrument tones and that are without the metallic `sound and harshness found in the tones produced by most electrical musical instruments.

Another object of this invention is to provide an instrument of the character mentioned in which the vibrations of the bass strings, for example the D and G strings of a violin, are given dominance or vbrought out with greater distinctness than the higher strings or the E and A strings, whereby the desired cello tones may be produced by the musician with ease. In the typical violin and in the usual instrument of this class having an electrical pick-up the E string beingot small diameter and under relatively high tension, produces tones that dominate the tones of the heavier strings. In the instrument provided by the present invention this -the same manner as a typicalviolin type instrument.

Another object of this invention is to provide an instrument of the character mentioned in which the body or sound box of the instrument is sub- 15 stantially non-vibratile and incapable of producing vibrations that may aifect the electrical pickup means.

Another object of this invention is to provide an electrical stringed instrument of the character 20 mentioned embodying a novel floating bridge carried by the diaphragm or armature of the pickup unit.

A further object of this invention is to provide a particularly Aeffective electro-magnetic pick-up 25 unit that is light in weight, small and compact, and adapted to be embodied in a typical stringed instrument with but slight modification of the usual instrument construction. l

The various objects and features of my inven- 30 tion will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawing, in which: 35

Fig. 1 is a top or plan view of an instrument of the present invention. Fig. 2 is an enlarged fragmentary vertical detailed sectional view taken as indicated by line 2 2 on Fig. 1, illustrating the principal parts of the pick-up. Fig. 3 is a frag- '40 ment-ary vertical detailed sectional view taken as indicated by line 3-3 on Fig. 2. Fig. 4 is a'fragmentary bottom elevation of the pick-up .being a view taken as indicated by line 4-4 on Fig. 2, and Fig. 5 is a perspective view of the under side 45 of the pick-up unit apart from the instrument body with a wiring diagram of the circuits em.- bodied in the instrument.

The improved stringed instrument of the present invention includes, generally, a body il, a 5 plurality of tensioned vibratile strings Il carried by the body l0, and an electrical magnetic pick-up I2 on the body Ill carrying a floating bridge I3 which engages the strings il between their ends.

The body lo or the musical instrument may be with the ybottom of the-body l@ to make the upin the drawing'the body it may be constructedv of wood and may have the same shape as the body of a conventional violin. If desired the pick-up I2 may be applied to or embodied in the body of a typical violin which has been modified to make it substantially non-vibratile. In accordance with the broader aspects of the invention the instrument body it may be made substantially non-vibratile and non-resonant in any suitable manner. In practiceit has been found desirable to provide a plurality of spaced braces or posts i4 in the interior of the hollow body l@ to connect its upper normally vibratile wall l5 per wall I5 substantially rigid and'non-vibratile. The ppsts i4 are rigidly secured to the top wall i5 and are effectivein lpreventing vibration of the same. The usual openings i6 in the upper body wall l5 may be closed with fabric il or the like, tofurthendampen the body i0. In addi' tion to the posts M and the vfabric il the body It! may be lined or lfed with felt, kapok o r the like to lessen or prevent vibration of the body or the resonance/of the body. The body i0 is provided with the usual neck i8. The neck t8 is rigid with the body l0 and projects outwardly from the body. The conventional nger-board i9 is that the pick-up l2 1s Smau, in@

provided on the neck i8 and the outer portion of the neck i8 carries the string tensioning pegs The strings i'l are stretched across the upper face of the body I0 and the iingerboard is and constitute the vibratile elements or sound propagating elements of the instrument. In the case illustrated there are four spaced strings il which may be considered as the conventional E, A, D and G strings of the violin. The strings it 'are tensioned between a tail piece 2| o n the body Ni and the pegs 2t at the outer end of the neck it. The pegs may be employed to tension and tune the strings il in the usual manner. It is a feature 'of the invention that the strings li may` be of any desired or selected character. For example, the strings li may be metal strings,`gut strings, gut string wound with silk or metal, and the different strings may beof different mate,-

`rials and construction. In accordance with the' usual practice the strings ll are graduated in diameter. 'While the strings li may be tuned diierently I will herein designate them as the E, A, D and G strings, the E string'being the smallest in diameter and the G string being the largest in diameter. Fig. 2 of the drawing illustrates the relationship between the E, A, D and G strings and the several 'parts of the pick-up I2 which relationship will be Ahereinafter described. Y i

The pick-up i2 is provided to convert the vibrations of the "strings or vibrations produced -byH the strings into amodulated .electric current ,which in turn maybe reproduced as sound truly representative of the tone producing vibrations of the strings. It is a feature of the invention t in weight, and

readily arranged on the body Il l, of the musical instrument.. An opening 22 i formed or ,cut in the upper wall l5 of the pick-up I2. The opening 22 vis spaced from the tail-piece 2l in the direction of the neck l9 and is shaped to receive a mounting plate 23 of the pick-up l2. In the particular arrangement illus- For example, where the e,171,4so

trated in the drawing the opening 22 has a straight outer wall and a curved inner or rear wall. The mounting plate f23 may be a simple casting of aluminum, Bakelite, or other nonmagnetic material. The plate 23 rests down- 5 f elongated and 'its major horizontal axis extends transversely of the strings Il. Two downwardly projecting bosses 26 are provided on the under side of the mounting plate 23. The bosses 26 are adjacent the `opposite ends of the opening 25 and 15 project downwardly into the hollow instrument body I0. The bosses 26 are positioned with respect to the opening 25 so that their upper sides or ends constitute upwardly facing shelves orv The electrical pick-up l2 further includes aI magnet 28 carried by the Vbosses 26 of the plate 23 to be within'f'the hollow instrument body it. The

magnet 28 is a permanent magnet and is prefer- 25 secured togetherto constitute a single laminated 3c magnet of the character illustrated in the drawing'. In the particular case shown inthe drawing the magnet 28 is formed of two layers ror a laminae which are preferably adhesively secured v together by water glass or silicate oi soda, onse Y .the like, to prevent the development o2 vibration between them. The magnet 28 is arrmiged with its arms extending in the same general direction as the strings ll and screws 29'are passed upwardly through openingsdin Vthe arms of the mag- 4e net and are threaded in openings .30 in the bosses 2d t'o secure the magnet arms to the bosses.

Each arm of the magnet 28`is provided with a pole piecel.` The 'pole pieces 3l are formed of magnetic material to constitute extensions oi`4l5' the magnet 28. The pole pieces 3l are preferably substantially L-shaped having inner parts or arms 3l engaging upwardly against the under sides of the magnet 28. \'Ihe heads 29a vof the screws 29 may clamp'the -pole piece arms 3i* 50 upwardly a`gainst the arms of the magnet 23. Silicate of soda may be employed to adhesively secure the magnet 28 to the bosses 26 and to secure the pole piece arms 3|'5x to the magnet arms to prevent rattle and relative vibration at these points. The pole pieces proper, 3l, project upwardly or outwardly from their arms 31a to be in spaced parallel relation and to be spaced from the arms of the magnet 28. The pole pieces 3l are elongate 4or rectangular in transverse cross 50 section and have their longest transverse axis substantially parallel with the strings il. The upper ends of the polepieces 3l are flat and lie in a plane adjacent or slightly above the -plane occupied by the 'shoulders 21.

The pick-up l2 further includes an induction coil C surrounding each pole piece 3l. -Thacoils C are in the nature of wrappings orwindings of wire on spools 32. ,The spools 32 are of insulating material -and may rest on the arms 3hof them pole pieces to support the coils in position. The pole pieces 3| protrude clear of the upper ends of the coil spools 3 2. A wire 83 electrically connects the two coils C and a lead extends from each coil C. n clip` or terminal 35 is carried by 7 ,The opening 25 is horizontally m shouldersvZl at the opposite ends of the opening g@ section 43a.

by one of the leads 34 whereby the coils C are grounded or connected with the magnet 23. The leads 34 extend through the body l0 to plug jacks 36. The plug jacks 36 are adapted to receive plugs 31 on electrical leads 38 extending to a suitable amplifying and loud/speaker unit 39; The plug jacks 36 may be suitably secured in openings in the side wall of the instrument body II). 'I'he invention provides a tone control 40 and a. volume control 4I on the instrumentl body I0 to govern the action or operation of the pick-up I2. The controls 40 and 4| are suitably connected in the coil leads 34. 'Ihe handles or knobs 4|!IIL and 4|, respectively, of the controls 40 and 4| project from the outer surfaces of the instrument body l I0 to be conveniently accessible to the musician.

An important element of the pick-up I2 yis a diaphragm or'armature 43 responsive to vibra- 'carries the bridge I3 and .floats or is supported for controlled or dampened vibration. The armature 43 is an elongate member formed of magnetic material. In the preferred construction illustrated in the drawings the'armat'ure 43 is a plate-like member provided on its outer side with a section 43a of Wood, hard rubber composition, Bakelite or other non-magnetic material. The under side of the armature 43 is flat and substantially horizontal to oppose the upperfends of the pole pieces 3| while the upper side of the armature section 43 is curved or convex as best illustrated in Fig. -2 of the drawing. The armature 43 is supported on the shelves or shoulders 21 to be adjacent and in spaced relation to the outer ends of the pole pieces 3|. The bridge I3 is supported on the armature 43 and the armature is mounted on the shoulders 21 in such a manner that the assembly of the bridge I3 and the armature 43 may move or vibrate in the desired manner in response to vibration of the strings I I. The bridge I3 may be of typical construction and may be formed of wood, or the like. The upper edge of the bridge I3 has notches 44 receiving the spaced strings II. The bridge I3 is provided at its lower or inner end with broadened feetl 45, which rest on the outer surface of the armature The opposite end portion of the armature 43 are' supported on the spaced shoulders 21.

In accordance with the invention the end portion of the armature 43 under or in close relation to the-E and A strings is supported on its shoulder -ing the last named end of the armature 43 may be laminated and may include a layer 48 of yielding rubber and one or more layers 49 of wood, felt, cork, paper or similar mat rial. The cushion formed of the layers 48 and 49 is preferably somewhat thicker than the cushion 46. Because of this relationship between th cushions 46 and 43-43 the armature 43 is ightly inclined Awith respect to the plane occupied by the ends of the 4 pole pieces 3|. The non-magnetic section 43a of the armature 43 has an inclined under surface 50 to compensate for this inclination of the armature 43 so that the bridge I3 is supported in its correct non-inclined position. A protective or retaining plate 5| may beAVH secured to the upper side of the mounting plate 23 to partially overlie the opening 25. The plate 5I is operable to prevent loss or displacement of the armature 43 and prevents the entrance of objects into the pick-up I2. The plate 5| is preferably formed of nonmagnetic material and does not engage the bridge I3 or the armature 43. The assembly of the bridge I3 and armature 43 supported by the cushions 46 and 48-49 is floating Aor capable of limited movement caused by vibration of the vibratile strings II. When a. string I| is bowed, plucked, or otherwise vibrated the assembly of the iioating bridge I3 and armature 43 is put into vibration and the vibration of the armature \`43 varies the reluctance of the magnetic circuit of the pick-up I2 inducing a current in the coils C. This current carried by the leads 34 and 36 is amplified and converted into sound by the unit 39, the sound being truly representative of the vibration of the string II. It will be understood how movement of the armature 43 resulting from vibration of a string or strings |I disturbs the magnetic eld or varies the reluctance of the magnetic eld concentrated at the outer ends of the pole pieces 3|. The magnetic circuit of the magnet 28 and the pole pieces 3| is linked with the coils C and variation of its reluctance induces a current in the coils which current has characteristics proportional to and truly representative of the vibrations of the string or'strings II.

The cushion 46 supporting the end of the armature 43 carrying the end portion of the bridge i3 which engages the tensioned light E string' is substantially unyielding and forms what may be considered a pivotal mounting for the bridge and armature assembly. The cushion 48-49 supporting the other end of the armature and bridge assembly is yielding so that the end of the bridge |3 engaged by the heavy strings D and G may have considerably more movement or vibration than the end` of the bridge engaged by the E string. The tensioned strings II of course exert a considerable downward pressure on the bridge i3 which maintains the armature 43 in tight engagement with its cushions 46 and 43-49. The lighter E and A strings may in some instances be under greater tension than the heavier D and G strings and may exert a heavier downward force on the bridge I3 and the armature 43. This heavier downward force or pressure is transmitted to the relatively unyielding cushion 46. The relationship between the cushions 46 and 48-43 is such that vibration of the A, D and G strings produces a greater vibration or movement of the armature 46 than vibration of the E string so that the pick-up I2 is more sensitive or more responsiveto the vibrations of the A, D and G strings than it is to the vibrations of the E string. Thus the pick-up I2 of the invention automatically compensates for the normal dominance of the E string over the other strings of the instrument. Accordingly, the musician is able to obtain tones of the desired character, intensity and volume from the A, D and G strings with ease. It is to be understood, of course, that the amplifying and loud speaker unit 39 is operable to produce tones from any and all of the strings I I of any desired volume.

'I'he instrument provided by the present invention may be handled and played in the same manner as any conventional violin class instrument. The pick-'up I2 and the associated parts are all light in weight and do notmaterially affect or Ibe limited or restricted to the fspeclic details herein set forth, but wish to reserve to myself any variations or modications that may appear to those skilled in the art or iall within the scope of the following claims.

Having described my invention, I claim:

l. A pick-up for use on a, stringed musical instrument having a vibratory part, the pick-up comprising a magnet having spaced pole pieces,

induction coils around the pole pieces, a support member carrying the magnet and having'spaced shoulders, an amature in the eld of magnetic ux betwen-the pole pieces and having lo'ngi'- tudinally spaced portions in supporting engagement with said part, and cushions mounting the ends ofthe armature onthe shoulders whereby the armature is supported independently of the pole pieces to be vibrated by the said part, one of comprising a magnet having spaced pole pieces,

said vcushions being more yieldable than the other whereby the amature is more responsive to the vibrations of one end portion of the said part than to the vibrations of the otherend portion of said part.

2. A pick-up for use on a stringed musical instrument'having a vibratory part, the pick-up induction coils around the pole pieces, a support member carrying the magnet and having spaced shoulders, an armature in the eld of magnetic flux between the pole pieces and having longitudinally spaced portions supporting the ends of Said'part, and yieldable material supporting thev ends of the amature on the shoulders whereby the armature is responsive to vibration of the saidpart, the said material on one shoulder being more yieldable than the material on the other shoulder. y

ii. A pick-up for use on a stringed musical instrument having a vibatory part, the pick-up comprising a support member having spaced shoulders, a magnet carried by the-member and havingl pole pieces, induction coils on the pole pieces, an elongate armature arranged in the iield of magnetic ux between the pole pieces and car- I rying the vibratory part. and vcushions on the shoulders having supporting engagement with the opposite end portions o! the armature whereby` the amature is vibrated by the said part, one of said cushions comprising yielding resilient material. the other cushion comprising substantially unyielding material.

4. A pick-up for a musical instrument havingl a hollow body provided withA an opening in its upper wall and having a vibratory part, the pickup including a mounting member on said upper wall entering said opening, a magnet in the body carried by said member and having pole pieces, induction coils around the pole pieces, an elongate armature arranged withinthe field of magnetic ux between the pole pieces adapted to carry said part to be vibrated by said part, and means supporting two longitudinally spaced parts of the armature on the said member, one of said means being yieldable and vibration dampening, the other of said means being substantially unyielding and vibration dampening. A

5. A pick-up for a stringed musical instrument embodying a vibratile part and having a hollow body provided with an opening in its upper wall, the pick-up comprising a mounting member on said upper wall entering said opening, spaced shoulders on the said member, a magnet in the body carried. by saidv member and having pole pieces projecting outwardly, induction coils around the pole pieces, an armature adapted to be vibrated by said part and arranged in adjacent spaced relation to the, outer ends of the pole pieces, substantially unyielding cushion means supporting one end portion of the armature on one of the said shoulders and `yieldable cushion means supporting the other end portion of the amature on the other shoulder to be responsive to vibrations of the strings.

6. yA pick-up for a stringed instrument having a hollow body and a vibratory part, the pick-up comprising a magnet having spaced pole pieces, means supporting the lmagnet in the body to haveits pole pieces project upwardly, induction coilsarouud the pole pieces, an armature arranged in spaced in clined relation to the plane occupied by the upper ends of the pole pieces and supporting the vibrating part, and cushion means supporting the opposite end portions of the armature, the supporting means atLthe high end of the armature being yieldable. the supporting means at the low end of the armature being substantially unyielding '7. A pick-up for use on astringed instrument n having a body and a vibratorypart, the pick-up on the magnet, induction coils around the polepieces, an armature supporting said part arranged in the opening and in the eld ot the magnetic flux between the pole pieces, and means supporting the oppositeends of the amature on' upper ends of the bosses. one of the said means being yieldable and the other of said means being substantially unyielding.

- FREDRAY H. KISHNGBURY. 

